This invention relates to a telecommunications system for persons and things, and more specifically to a telecommunications systems utilizing a global position satellite information in the determination of the location of a person or thing.
Various systems have been used in the prior art to locate persons or things based on global positioning satellite systems for receiving navigation signals from satellites in orbit about the earth. One such system is described in U.S. Pat. No. 5,043,736 which describes a system including both a remote unit and a base unit for ascertaining the global positioning of individuals or objects utilizing a cellular telephone network in combination with a satellite navigation system. The remote unit includes a radio frequency receiver having the capability of receiving navigational signals from satellite in orbit about the earth such as a global positioning or GPS receiver. The base unit also includes a microprocessor to analyze the coded signal and a cellular telephone system including a modem for transmitting signals to the base unit. The remote unit, once activated, receives navigational signals from satellites above the earth and transmits those signals as indicative of the global positioning of the person or thing, with the signals thus received being stored in memory. At appropriate times, the stored position information is transmitted to the base unit by way of a cellular telephone system, and specifically, a modem therefore for transmitting the position information to the base unit.
The base unit thus receives and coordinates the location of the remote, decoding the position data transmitted through the cellular telephone system. That navigational or location information can then be displayed on a visual display at the base station to indicate the coordinates of the remote unit.
While the system described in the aforementioned patent has a number of advantages over other systems theretofore known, it nonetheless is subject to certain disadvantages. For one thing, the system as described in the foregoing prior art patent must be left in the "on" position so that the base unit can continuously track the position of the remote unit. The system as described in the foregoing patent has no capability of activating the remote unit from the base station. That can be a distinct disadvantage in those situations where the remote unit is in the possession of, for example, a small child who has been abducted. Such a small child might not be able to turn on the remote unit, and thus it must be left "on" at all times. That, in turn, adversely affects the useful life of the remote unit because of limitations of electrical power sources for the remote unit. In addition, such a system as described in the foregoing patent has no capability of providing any sort of video signals which might otherwise be used to assist in determining the location of the child or the identity of the perpetrator or perpetrators in the abduction. It is important, particularly with systems used for small children, that a remote unit have the capability of providing a video signal.
It is accordingly an object of the present invention to provide a telecommunications system for locating persons and things which overcomes the foregoing disadvantages.
It is a more specific object of the invention to provide a telecommunications system for locating persons and things which contains both a remote unit and a base station in which the remote unit not only has the capability of sensing global position but also has the capability of providing to the base station a video signal.
It is another specific object of the invention to provide a telecommunications system for locating persons and things having a remote unit which has the capability of being activated from a remote location such as the base station to provide reverse tracking.
It is yet another object of the invention to provide a telecommunications system for locating persons and things, and particularly a remote unit which has been miniaturized so as to be capable of being worn by, for example, a small child.
It is still another object of the present invention to provide a telecommunications system for locating persons and things, and particularly a remote unit therefore, which is not only miniaturized but also can be conveniently camouflaged so that its identity as a remote unit is not immediately apparent.
These and other objects and advantages of the invention will appear more fully hereinafter from the following description of the invention and the drawings.